title: Issues relevant to the assessment of chemically induced chromosome damage in vivo and their relationship to chemical mutagenesis.
abstract: Rats have been exposed by different routes of administration (inhalation, orally and intraperitoneally) to known mutagens and their bone-marrow cells sampled at different times to determine the extent of chromosome damage. The mutagens investigated were ethyl methanesulphonate, mitomycin C, trimethylphosphate, benzene and vinyl chloride, at single and/or multiple doses (5 consecutive daily). Various categories of chromosome damage were observed in all cases. However, the extent of damage due to chromosome and chromatid gaps was greater than, and generally increased in parallel with, other categories of damage. It has been suggested tht chromosome and chromatid gaps are indicative of toxic phenomena but this study suggests that such aberrations could be useful and sensitive indicators of chemically induced genetic damage. In addition the study has also confirmed that single exposure is as effective as multiple exposure in producing chromosome damage and that the correct sampling time is necessary to detect this damage. Therefore for screening purposes a time course sampling after a single treatment regime would be suitable for detecting the mutagenic potential of a chemical.
mesh_terms: D000818:Animals; D001554:Benzene / Q000494:pharmacology; D001853:Bone Marrow / Q000648:ultrastructure; D002869:Chromosome Aberrations; D002875:Chromosomes / Q000187:drug effects*; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D008297:Male; D016685:Mitomycin; D008937:Mitomycins / Q000494:pharmacology; D009153:Mutagens / Q000494:pharmacology*; D051381:Rats; D014752:Vinyl Chloride / Q000494:pharmacology
chemical_list: D008937:Mitomycins; D009153:Mutagens; D016685:Mitomycin; D005020:Ethyl Methanesulfonate; D001554:Benzene; D014752:Vinyl Chloride